iequidoo's review: Make sure statistics are sent again after rewound system time

Author: Hocuri

deltachat-time/src/lib.rs

@@ -20,6 +20,11 @@ impl SystemTimeTools {
     pub fn shift(duration: Duration) {
         *SYSTEM_TIME_SHIFT.write().unwrap() += duration;
     }
+
+    /// Simulates the system clock being rewound by `duration`.
+    pub fn shift_backwards(duration: Duration) {
+        *SYSTEM_TIME_SHIFT.write().unwrap() -= duration;
+    }
 }
 
 #[cfg(test)]

src/statistics.rs

@@ -159,7 +159,19 @@ pub async fn maybe_send_statistics(context: &Context) -> Result<Option<ChatId>>
         let last_sending_time = context.get_config_i64(Config::StatsLastSent).await?;
         let next_sending_time = last_sending_time.saturating_add(SENDING_INTERVAL_SECONDS);
         if next_sending_time <= time() {
+            // Setting this config at the beginning avoids endless loops when things do not
+            // work out for whatever reason.
+            context
+                .set_config_internal(Config::StatsLastSent, Some(&time().to_string()))
+                .await?;
+
             return Ok(Some(send_statistics(context).await?));
+        } else if time() < last_sending_time {
+            // The clock was rewound.
+            // Reset the config, so that the statistics will be sent normally in a week.
+            context
+                .set_config_internal(Config::StatsLastSent, Some(&time().to_string()))
+                .await?;
         }
     }
     Ok(None)
@@ -184,14 +196,6 @@ pub(crate) async fn should_send_statistics(context: &Context) -> Result<bool> {
 async fn send_statistics(context: &Context) -> Result<ChatId> {
     info!(context, "Sending statistics.");
 
-    // Setting this config at the beginning avoids endless loops when things do not
-    // work out for whatever reason.
-    context
-        .set_config_internal(Config::StatsLastSent, Some(&time().to_string()))
-        .await
-        .log_err(context)
-        .ok();
-
     let chat_id = get_statistics_bot(context).await?;
 
     let mut msg = Message::new(Viewtype::File);

src/statistics/statistics_tests.rs

@@ -43,6 +43,28 @@ async fn test_maybe_send_statistics() -> Result<()> {
     Ok(())
 }
 
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_rewound_time() -> Result<()> {
+    let alice = &TestContext::new_alice().await;
+    alice.set_config_bool(Config::StatsSending, true).await?;
+
+    const EIGHT_DAYS: Duration = Duration::from_secs(3600 * 24 * 14);
+    SystemTime::shift(EIGHT_DAYS);
+
+    maybe_send_statistics(alice).await?.unwrap();
+
+    // The system's time is rewound
+    SystemTime::shift_backwards(EIGHT_DAYS);
+
+    assert!(maybe_send_statistics(alice).await?.is_none());
+
+    // After eight days pass again, statistics are sent again
+    SystemTime::shift(EIGHT_DAYS);
+    maybe_send_statistics(alice).await?.unwrap();
+
+    Ok(())
+}
+
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
 async fn test_statistics_one_contact() -> Result<()> {
     let mut tcm = TestContextManager::new();